The five permanent members of the UN Security Council have said they are committed to making the Middle East a nuclear weapons-free zone, a move which would ultimately force Israel to scrap any nuclear weapons it has.
In a statement in New York on Wednesday, China, France, Russia, the US and UK reaffirmed their backing for a 1995 resolution on the issue.
The backing from the so-called P5 members of the Security Council - all of them states with nuclear weapons - came as the UN hosts a conference aimed at strengthening the 1970 nuclear Non-Proliferation Treaty (NPT).
"We are committed to a full implementation of the 1995 NPT resolution on the Middle East and we support all ongoing efforts to this end," the statement said.
"We are ready to consider all relevant proposals in the course of the (NPT) Review Conference in order to come to an agreed decision aimed at taking concrete steps in this direction."
US support for the idea of creating such a zone could be unwelcome to Israel, is largely believed to have nuclear weapons despite refusing to confirm or deny the claims.
Israel has said it could only consider supporting such a zone once there is Middle East peace.
Wednesday's statement from the P5 does not give a mandate for setting up the zone and the 1995 resolution only calls for "practical steps" towards a zone, leaving open how and when it would come into existence.
The permanent Council members also called for all states to join the NPT, and to disarm if they have nuclear weapons.
"We attach great importance to achieving the universality of the NPT," they said.
"We urge those states that are not parties to the treaty to accede as non-nuclear-weapon states and pending the accession to the NPT, to adhere to its terms."
Egypt, which chairs a 118-nation bloc of non-aligned developing nations, has been circulating a proposal to the 189 signatories of the NPT calling for a conference by next year on ridding the Middle East of nuclear arms in which all countries in the region would participate.
"We have to have a conference, an international conference, whereby the nuclear powers, as well as the regional countries, would meet and discuss how to establish a zone free of nuclear weapons," Abul Gheit, Egypt's foreign minister, said during a visit to Cyprus.
"We are in discussions right now in the UN with the Americans, with the Russians, with the P5 ... and hopefully we would agree on terms of reference, on how to agree to establish that conference and when to meet, how to meet, who would be calling for that conference and how to pursue the issue in the immediate future."
The need has "doubled" for such a zone as Britain, Russia and the United States have done nothing to carry out their 1995 pledge to set it up, a statement read by Egypt's UN ambassador said.
The non-aligned states want Israel, which is believed to have some 200 atomic bombs, officially declare its arsenal and then join the NPT in order to disarm.
But diplomats at the conference say Arab states are pushing hard on the issue in exchange for their support for US-led efforts to curb Iran's nuclear programme.